1. Field
The present invention relates generally to soft handoff in communications systems, and more specifically, to soft handoff across different types of communication networks assisted by an end-to-end application protocol.
2. Background
Communications systems are used for transmission of information from one device to another. Today there are many different kinds of communication devices and many different kinds of communication networks that may be used. Examples of communication devices include, but are not limited to, a telephone, a cellular phone, a desktop computer, a laptop computer, a personal digital assistant, a pager, and the like. Different communication networks include, but are not limited to, a Code Division Multiple Access (CDMA) 1x network, a Local Area Network (LAN), a wireless LAN, the Internet, a Wideband CDMA (W-CDMA) network, a General Packet Radio Service (GPRS) network, etc. As shown, a user has many options to choose from in selecting a communication system for his or her use.
With the many different communication options available to a user, there may be times when a user wishes to change the way in which he or she is achieving the communications while engaged in a current communication link. For example, the user may wish to switch networks or devices during a call or a session without losing the call or session. A call or session is a communication state shared by two or more parties that have established communication link(s) between them; one example of a call or session is a Voice over IP call. A need exists, therefore, for systems and methods to enable a user to be able to switch networks or devices during a call or a session without losing the call or session.